Cajal bodies are developmentally regulated during pollen development and pollen tube growth in Arabidopsis thaliana

REGINA SCARPIN; LORENA SIGAUT; LÍA PIETRASANTA; SHEILA MCCORMICK; BINGLIAN ZHENG; JORGE MUSCHIETTI

MOLECULAR PLANT

OXFORD UNIV PRESS

Lugar: Oxford; Año: 2013 vol. 6 p. 1355 - 1357

1674-2052

Cajal bodies (CBs) are sub-nuclear bodies first described in neurons byRamon y Cajal in 1903 and subsequently characterized in both plant and animals(Gall, 2003). They appear close to the nucleoli as discrete foci whose size andnumber vary during the cell cycle (Strzelecka et al., 2010). They are dynamicstructures that move, fuse and separate depending on the transcriptional statusof the cell (Cioce and Lamond, 2005). CBs are involved in assembly andtrafficking of small nucleolar ribonucleoproteins (snoRNPs) and in assembly andtrafficking of spliceosomal small nuclear ribonucleoprotein (snRNPs) complexesthat are involved in mRNA splicing (Cioce and Lamond, 2005; Gall, 2003). Cajalbodies also contain components of the machinery involved in siRNA-mediatedsilencing and in methylation of repetitive DNA (Li et al., 2006). Vertebrate Cajalbodies contain a high concentration of coilin, a protein that is widely used as amolecular marker for CBs (Cioce and Lamond, 2005). In Arabidopsis there is adistant homolog of vertebrate coilin (Collier et al., 2006). An Arabidopsis mutant,ncb1 (no cajal bodies 1), lacks CBs due to a single base change at a splice site inArabidopsis coilin (At1g13030), resulting in total disassembly of CBs (Collier etal., 2006; Fang and Spector, 2007). A tagged version of Arabidopsis coilinrestored the formation of CBs in ncb-1 (Collier et al., 2006). Despite thefunctional relevance of CBs in RNA processing, knock-out mutants for coilin havebeen obtained in mice, although they exhibit reduced viability (Walker et al.,2009), whereas Arabidopsis and Drosophila that lack CBs are completely viableand normal (Collier et al., 2006; Liu et al., 2009). These results therefore suggestthat the processes that normally occur in the CBs can be carried out in thenucleoplasm.